The present invention relates to a wet clutch disc in which a friction facing is adapted to be lubricated by lubricating oil.
As shown in FIG. 2, which is a fragmentary sectional view, in a known wet clutch disc, an output shaft 1 is provided with passages 2 for feeding lubricating oil toward friction facings 3. However, in the known disc, since a part of the lubricating oil flowed from the passages 2 is ununiformly applied to friction washers 5, a frictional force of the washers 5 and a hysteresis torque caused thereby become unstable, so that torque vibration may not be absorbed effectively and a large noise may be generated in a driving system after a long use.
Further, in the known structure, when torsion springs 8 connecting a flange 6 of a hub and side plates 7 together are deformed radially outwardly by a centrifugal force, the springs 8 may undesirably engage with edges 9 of openings in the plates 7.